Mediterranean and Japanese diets vs. neurodegenerative diseases

Abstract

Neurodegenerative diseases such as Alzheimer's disease (AD) have become very important in recent years due to the increase in the number of cases worldwide, becoming a major problem for Public Health. This has been due to an increase in life expectancy, which translates into a greater number of elderly people at risk of suffering from chronic and degenerative diseases. AD is the most common type of dementia assuming cognitive decline that ultimately leads to a decrease and loss of patient autonomy. It is characterized by the loss of the neuronal synapse due to the presence of senile plaques (PS) formed by the accumulation of ?-amyloid peptides at the extracellular level, and aggregates of the hyperphosphorylated tau protein at the intracellular level, giving rise to neurofibrillary tangles (ONFs). ). This entails an increase in oxidative stress and inflammatory processes that ultimately produce neuronal apoptosis.

Currently, there is no pharmacological treatment capable of reversing this pathology, so one of the strategies being used is intervention at the level of modifiable risk factors that have been associated with the development of AD, such as example, cardiovascular disease. Lifestyle, especially dietary habits and physical activity seem to play an important role in preventing the onset of AD and other neurodegenerative diseases. The Mediterranean diet and the Japanese diet are considered worldwide as prudent, healthy and nutritionally balanced diets. Therefore, the analysis of both diets in the context of the decreased risk of developing AD is of great interest. The objective of this work is to carry out a bibliographic review on the current evidence about the association of these diets with cognitive function and AD.

Both the Mediterranean and Japanese diets seem to help minimize the likelihood of AD. The high content of antioxidant and anti-inflammatory substances seems to be the reason. The main foods and nutrients responsible for these actions are: polyphenols, carotenoids, and isothiocyanates from vegetables, fruits, and teas; omega 3 polyunsaturated fatty acids from oily fish and certain oils; monounsaturated fatty acids present in olive oil; fat-soluble and water-soluble vitamins and minerals; and soy isoflavones, among others. All these components can act synergistically to prevent disease directly or indirectly. In addition, regular physical activity is also promoted as a healthy lifestyle habit.

Currently, the data related to this association remain inconsistent possibly due to the paucity of randomized controlled trials and large-scale observational and clinical epidemiological studies with standardized study designs and methods. However, the results available today allow establishing a negative relationship between monitoring these dietary patterns and the risk of AD.